Kinetics:
The rate dynamics in chemical or physical systems.
JoVE Bioengineering
Adhesion Frequency Assay for In Situ Kinetics Analysis of Cross-Junctional Molecular Interactions at the Cell-Cell Interface
Biomedical Engineering Department, Georgia Institute of Technology
An adhesion frequency assay for measuring receptor-ligand interaction kinetics when both molecules are anchored on the surfaces of the interacting cells is described. This mechanically-based assay is exemplified using a micropipette-pressurized human red blood cell as adhesion sensor and integrin αLβ2 and intercellular adhesion molecule-1 as interacting receptors and ligands.
JoVE General
Application of Stopped-flow Kinetics Methods to Investigate the Mechanism of Action of a DNA Repair Protein
Molecular Biology and Biochemistry Department, Wesleyan University
Msh2-Msh6 is responsible for initiating repair of replication errors in DNA. Here we present a transient kinetics approach towards understanding how this critical protein works. The report illustrates stopped-flow experiments for measuring the coupled DNA binding and ATPase kinetics underlying Msh2-Msh6 mechanism of action in DNA repair.
JoVE General
The Importance of Correct Protein Concentration for Kinetics and Affinity Determination in Structure-function Analysis
We apply label-free protein interaction analysis using Biacore X100 for structure-function analysis of the binding of several cystatin B mutants to papain through kinetic characterization. Calibration-free concentration analysis (CFCA) measures the concentration of protein with retained binding activity without the need for a standard curve. We show that confirmation of concentrations using CFCA increases the reliability of the kinetic analysis and that kinetic constants can reliably be determined even if the activity of a recombinant protein is reduced.
JoVE General
Imaging G-protein Coupled Receptor (GPCR)-mediated Signaling Events that Control Chemotaxis of Dictyostelium Discoideum
Here, we describe detailed live cell imaging methods for investigating chemotaxis. We present fluorescence microscopic methods to monitor spatiotemporal dynamics of signaling events in migrating cells. Measurement of signaling events permits us to further understand how a GPCR-signaling network achieves gradient sensing of chemoattractants and controls directional migration of eukaryotic cells.
JoVE Bioengineering
Microfluidic Mixers for Studying Protein Folding
1Department of Physics and Astronomy, Michigan State University, 2Department of Mechanical Engineering, Hong Kong University of Science and Technology, 3Center for Biophotonics, University of California, Davis
In this work we explain the fabrication and use of a microfluidic mixer capable of mixing two solutions in ~8 μs. We also demonstrate the use of these mixers with spectroscopic detection using UV fluorescence and fluorescence resonance energy transfer (FRET).
JoVE Bioengineering
Combinatorial Synthesis of and High-throughput Protein Release from Polymer Film and Nanoparticle Libraries
Department of Chemical and Biological Engineering, Iowa State University
This method describes the combinatorial synthesis of biodegradable polyanhydride film and nanoparticle libraries and the high-throughput detection of protein release from these libraries.
JoVE Immunology and Infection
Isolation of Fidelity Variants of RNA Viruses and Characterization of Virus Mutation Frequency
Viral Populations and Pathogenesis lab and CNRS 3015, Institut Pasteur
The present article describes the steps required to isolate and characterize RNA polymerase fidelity variants of RNA viruses and how to use mutation frequency data to confirm fidelity changes in tissue culture.
JoVE Bioengineering
Rotating Cell Culture Systems for Human Cell Culture: Human Trophoblast Cells as a Model
1Department of Microbiology and Immunology, Tulane University Medical School, 2Physician/Scientist Program, Tulane University Medical School, 3Department of Molecular and Cellular Biology, Baylor College of Medicine
Traditional, two dimensional cell culture techniques often result in altered characteristics with respect to differentiation markers, cytokines and growth factors. Three-dimensional cell culture in the rotating cell culture system (RCCS) reestablishes expression of many of these factors as shown here with an extravillous trophoblast cell line.
JoVE General
Method for Measurement of Viral Fusion Kinetics at the Single Particle Level
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 2Howard Hughes Medical Institute, Harvard Medical School
We present an in vitro, two-color fluorescence assay to visualize the fusion of single virus particles with a fluid target bilayer. By labeling viral particles with fluorophores that differentially stain the viral membrane and its interior, we are able to monitor the kinetics of hemifusion and pore formation.
JoVE General
Measuring the Kinetics of mRNA Transcription in Single Living Cells
RNA polymerase II transcriptional kinetics are measured on specific genes in living cells. mRNAs transcribed from the gene of interest are fluorescently tagged and using Fluorescence Recovery After Photobleaching (FRAP) the in vivo kinetics of transcriptional elongation are obtained.
JoVE General
Combining QD-FRET and Microfluidics to Monitor DNA Nanocomplex Self-Assembly in Real-Time
1Mechanical Engineering, Johns Hopkins University, 2Biomedical Engineering, Duke University, 3Biomedical Engineering, Johns Hopkins University
We present a novel and powerful integration of nanophotonics (QD-FRET) and microfluidics to investigate the formation of polyelectrolyte polyplexes, which is expected to provide better control and synthesis of uniform and customizable polyplexes for future nucleic acid-based therapeutics.
JoVE General
Monitoring Equilibrium Changes in RNA Structure by 'Peroxidative' and 'Oxidative' Hydroxyl Radical Footprinting
1Department of Chemistry, Hunter College, 2Department of Biochemistry, Albert Einstein College of Medicine
This protocol describes how to quantify the Mg(II)-dependent formation of RNA tertiary structure by two methods of hydroxyl radical footprinting.
JoVE Immunology and Infection
Real-time Imaging of Leukotriene B4 Mediated Cell Migration and BLT1 Interactions with β-arrestin
Microbiology and Immunology, James Graham Brown Cancer Center, University of Louisville
This paper describes the methodology to determine the chemotactic response of leukocytes to specific ligands and identify interactions between the cell surface receptors and cytosolic proteins using live cell imaging techniques.
JoVE Immunology and Infection
Dissecting Host-virus Interaction in Lytic Replication of a Model Herpesvirus
1Center for Autophagy Research, Department of Internal Medicine, UT Southwestern Medical Center, 2Department of Microbiology, UT Southwestern Medical Center
We describe a protocol to identify key roles of host signaling molecules in lytic replication of a model herpesvirus, gamma herpesvirus 68 (γHV68). Utilizing genetically modified mouse strains and embryonic fibroblasts for γHV68 lytic replication, the protocol permits both phenotypic characterization and molecular interrogation of virus-host interactions in viral lytic replication.
JoVE Bioengineering
Ex vivo Mimicry of Normal and Abnormal Human Hematopoiesis
1Department of Chemical Engineering and Chemical Technology, South Kensington campus, Imperial College London, 2Department of Hematology, Northwick Park & St. Mark's campus, Imperial College London
A 3D culture system for hematopoiesis is described using human cord blood and leukemic bone marrow cells. The method is based on the use of a porous synthetic polyurethane scaffold coated with extracellular matrix proteins. This scaffold is adaptable to accommodate a wide range of cells.
JoVE General
Photoconversion of Purified Fluorescent Proteins and Dual-probe Optical Highlighting in Live Cells
Department of Molecular Physiology and Biophysics, Vanderbilt University
This protocol describes a general approach to perform photoconversion of fluorescent proteins on a confocal laser scanning microscope. We describe procedures for the photoconversion of puried protein samples, as well as for dual-probe optical highlighting in live cells with mOrange2 and Dronpa.
JoVE Bioengineering
Generation and Recovery of β-cell Spheroids From Step-growth PEG-peptide Hydrogels
The following protocol provides techniques for encapsulating pancreatic β-cells in step-growth PEG-peptide hydrogels formed by thiol-ene photo-click reactions. This material platform not only offers a cytocompatible microenvironment for cell encapsulation, but also permits user-controlled rapid recovery of cell structures formed within the hydrogels.
JoVE Neuroscience
Assaying β-amyloid Toxicity using a Transgenic C. elegans Model
1Institute for Behavioral Genetics, University of Colorado, 2Integrative Physiology, University of Colorado
The intensely studied nematode worm Caenorhabditis elegans can be transgenically engineered to express the human β-amyloid peptide (Aβ). Induced expression of Aβ in C. elegans muscle leads to a rapid, reproducible paralysis phenotype that can be used to monitor treatments that modulate Aβ toxicity.
JoVE Immunology and Infection
A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes
Institute for Bioscience and Biotechnology Research, University of Maryland
A novel directed evolution method specific to the field of thermostability engineering was developed and consequently validated for bacteriolytic enzymes. After only one round of random mutagenesis, an evolved bacteriolytic enzyme, PlyC 29C3, displayed greater than twice the residual activity when compared to the wild-type protein after elevated temperature incubation.
JoVE Clinical and Translational Medicine
Skeletal Muscle Gender Dimorphism from Proteomics
1Center for Proteomics, Smith College, 2Department of Molecular Biophysics and Biochemistry, Yale University, 3Department of Chemistry, Smith College, 4Department of Biological Sciences and Center for Proteomics, Smith College
A straight-forward set of methods to isolate and determine the identity of the most abundant proteins expressed in skeletal muscle. About 800 spots are discerned on a two-dimensional gel from 10 mg muscle; this allows for the determination of gender-specific protein expression. These methods will give equivalent results in most tissues.
JoVE Clinical and Translational Medicine
Method to Measure Tone of Axial and Proximal Muscle
1Department of Biomedical Engineering, Oregon Health and Science University, 2UCL Institute of Neurology, Queen Square, 3Department of Neurology, Oregon Health and Science University
We have developed a device (Twister) to study the regulation of tonic muscle activity during active postural maintenance. Twister measures torsional resistance and muscular responses in standing subjects during twisting of the body axis. The device can be flexibly configured to study various aspects of tonic control across the neck, trunk, and/or hips.
JoVE General
Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions
Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University
Vacuolar and cytosolic pH can be measured in live yeast (S. cerevisiae) cells using ratiometric fluorescent dyes localized to specific cellular compartments. We describe procedures for measuring vacuolar pH with BCECF-AM, which localizes to the vacuole in yeast, and cytosolic pH with a cytosolic ratiometric pH-sensitive GFP (yeast pHluorin).
JoVE General
Measuring Cell Cycle Progression Kinetics with Metabolic Labeling and Flow Cytometry
Faculty of Pharmaceutical Sciences, University of British Columbia
Tracking subtle changes in the progression and kinetics of cell cycle stages can be accomplished by use of a combination of metabolic labeling of nucleic acids with BrdU and total genomic DNA staining via Propidium Iodide. This method avoids the need of chemical synchronization of cycling cells, thereby preventing the introduction of non-specific DNA damage, which in turn affects cell cycle progression.
JoVE Immunology and Infection
In vivo Imaging of Transgenic Leishmania Parasites in a Live Host
1Interdisciplinary Immunology Program, University of Iowa, and the VA Medical Center, 2Department of Biochemistry, University of Iowa, and the VA Medical Center, 3Department of Internal Medicine, University of Iowa, 4Department of Molecular Microbiology, Washington University School of Medicine, 5Division of Dermatology, Harbor-UCLA Medical Center, Hanley-Hardison Research Center, 6Interdisciplinary Immunology Program, Iowa City VA Medical Center, 7Departments of Internal Medicine, Microbiology and Epidemiology, University of Iowa
An in vivo imaging system is used to generate quantitative measurements of murine infection with the Trypanosomatid protozoan Leishmania. This is a non-invasive and non-lethal method for detecting parasites expressing luciferase within many tissues throughout the course of chronic Leishmania spp. infection.
JoVE General
Labeling hESCs and hMSCs with Iron Oxide Nanoparticles for Non-Invasive in vivo Tracking with MR Imaging
For the evaluation of new stem cell therapies it is important to non-invasively track the injected cells in vivo. This video will show you how to label human mesenchymal and embryonic stem cells with iron oxide based contrast agents in vivo for subsequent MR imaging in vivo.
JoVE Bioengineering
Bioluminescence Imaging for Assessment of Immune Responses Following Implantation of Engineered Heart Tissue (EHT)
1Transplant and Stem Cell Immunobiology Lab (TSI) and CVRC, University Hospital Hamburg, University Heart Center Hamburg, 2Department of Experimental and Clinical Pharmacology and Toxicology, University Heart Center Hamburg, 3CT Surgery, Stanford University School of Medicine
This video demonstrates the use of in vivo bioluminescence imaging to study immune responses after implantation of Engineered Heart Tissue (EHT) in rats.
JoVE General
Protease- and Acid-catalyzed Labeling Workflows Employing 18O-enriched Water
Boston Biomedical Research Institute
Stable isotope labeling workflows employing 18O-enriched water (LeO-workflows) are versatile tools for quantitative and qualitative proteomics studies. In protease-assisted (PALeO) workflows, 18O-atoms are introduced by proteolytic cleavage and carboxyl oxygen exchange reactions mediated by proteases. In the acid-catalyzed (ALeO) workflow, 18O-atoms are introduced by carboxyl oxygen exchange at low pH.
JoVE Bioengineering
Quantitative FRET (Förster Resonance Energy Transfer) Analysis for SENP1 Protease Kinetics Determination
Department of Bioengineering, Bourns College of Engineering, University of California, Riverside
A novel method involving quantitative analysis of FRET (Förster Resonance Energy Transfer) signals is described for studying enzyme kinetics. KM and kcat were obtained for the hydrolysis of the catalytic domain of SENP1 (SUMO/Sentrin specific protease 1) to pre-SUMO1 (Small Ubiquitin-like MOdifier). The general principles of this quantitative-FRET-based protease kinetic study can be applied to other proteases.
JoVE Clinical and Translational Medicine
Murine Bioluminescent Hepatic Tumour Model
1Cork Cancer Research Centre, Mercy University Hospital and Leslie C. Quick Jnr. Laboratory, University College Cork, 2Department of Computer Science, University College Cork, 3South Infirmary Victoria University Hospital
This article describes a procedure for the induction of orthotopic bioluminescent liver tumours in mice, and subsequent analysis of tumour growth confined to the liver using live whole body luminescence imaging.
JoVE General
Semi-automated Optical Heartbeat Analysis of Small Hearts
1Development and Aging Program, The Sanford Burnham Institute for Medical Research, 2Cardiac Electrophysiology Group, Dept. of Physiology, Anatomy and Genetics, The Sanford Burnham Institute for Medical Research, 3Biology Department and Heart Institute, San Diego State University
We have developed a Semi-automated Optical Heartbeat Analysis method (SOHA) for analyzing high speed optical recordings from Drosophila, zebrafish and embryonic mouse hearts. We demonstrate the application of our methodology to the analysis of heart function in fruit fly and embryonic mouse hearts.
JoVE Bioengineering
Cell-based Calcium Assay for Medium to High Throughput Screening of TRP Channel Functions using FlexStation 3
This video provides a detailed protocol for studying the pharmacological profile of human TRPA1 channels using FlexStation 3. The protocol covers details of cell preparation, dye loading and operation of the microplate reader, FlexStation 3.
JoVE General
Direct Detection of the Acetate-forming Activity of the Enzyme Acetate Kinase
Department of Genetics and Biochemistry, Clemson University
A method for the determination of acetate kinase activity is described. This assay utilizes a direct reaction for determining enzyme activity and kinetics of acetate kinase in the acetate-forming direction with different phosphoryl acceptors. Furthermore, this method can be utilized for assaying other acetyl phosphate or acetyl-CoA utilizing enzymes.
JoVE Neuroscience
Expansion of Embryonic and Adult Neural Stem Cells by In Utero Electroporation or Viral Stereotaxic Injection
DFG - Research Center and Cluster of Excellence for Regenerative Therapies Dresden, Germany
Controlling the expansion of somatic stem cells is a major factor hampering their study and use in therapy. Here we describe a system to temporally control neural stem cells expansion during development and adulthood, which can be used to increase the number of neurons generated in the mouse brain.
JoVE Clinical and Translational Medicine
The Use of Reverse Phase Protein Arrays (RPPA) to Explore Protein Expression Variation within Individual Renal Cell Cancers
1Edinburgh Urological Cancer Group, University of Edinburgh, 2School of Medicine, University of St Andrews, 3Division of Pathology, University of Edinburgh, 4MRC Human Genetics Unit, MRC IGMM, University of Edinburgh, 5Department of Pathology, Western General Hospital, 6Breakthrough Breast Cancer Research Unit, University of Edinburgh, 7St Bartholomew's Cancer Institute, Experimental Cancer Medicine Centre, Queen Mary University of London
RPPA enables the protein expression of hundreds of samples, printed on nitrocellulose slides to be interrogated simultaneously, using fluorescently labelled antibodies. This technique has been applied to study the effect of drug treatment heterogeneity within clear cell renal carcinoma.
JoVE General
Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection
Department of Biochemistry, University of Toronto
Here we describe an assay that employs the power of microinjection coupled with fluorescent in situ hybridization in order to accurately measure the nuclear export kinetics of mRNA in mammalian somatic cells.
JoVE Neuroscience
Assaying DNA Damage in Hippocampal Neurons Using the Comet Assay
1Department of Radiation Oncology, University of Alabama-Birmingham, 2Department of Radiation Oncology, The Ohio State University Medical School, 3Department of Cell Biology, and Pharmacology and Toxicology, Comprehensive Cancer Center, University of Alabama at Birmingham School of Medicine, University of Alabama-Birmingham
The comet assay is an efficient way of detecting single- and double-strand breaks, including alkali-labile sites and DNA-DNA/DNA-protein cross-links on the DNA in all cells including hippocampal neurons. The method takes advantage of the differential migration of DNA in an electric field due to differences in amount of DNA damage.
JoVE Neuroscience
Kinematics and Ground Reaction Force Determination: A Demonstration Quantifying Locomotor Abilities of Young Adult, Middle-aged, and Geriatric Rats
1CullenWebb Animal Neurology & Ophthalmology Center, Riverview, NB, 2Department of Clinical Neurosciences, Faculty of Medicine, University of Calgary, 3Department of Comparative Biology and Experimental Medicine, University of Calgary, 4Department of Neuroscience, University of Calgary
Locomotion is often examined as a behavioural outcome in various models of disease in fields such as neuroscience and orthopedics. This video paper intends to describe a method for collecting ground reaction forces and kinematics from rats during unrestrained locomotion.
JoVE General
A High-throughput Method for Measurement of Glomerular Filtration Rate in Conscious Mice
1Division of Nephrology-Hypertension, Department of Medicine, University of California, San Diego, 2San Diego VA Healthcare System
Measurement of glomerular filtration rate (GFR) is the gold standard for kidney function assessment. Here we describe a high-throughput method which allows the determination of GFR in conscious mice by using a single bolus injection, determination of fluorescein isothiocyanate (FITC)-inulin in plasma and calculation of GFR by a two-phase exponential decay model.
JoVE Neuroscience
Quantitative Analysis of Synaptic Vesicle Pool Replenishment in Cultured Cerebellar Granule Neurons using FM Dyes
Membrane Biology Group, Centre for integrative Physiology, University of Edinburgh
A live fluorescence imaging technique to quantify the replenishment and mobilisation of specific synaptic vesicle (SV) pools in central nerve terminals is described. Two rounds of SV recycling are monitored in the same nerve terminals providing an internal control.
JoVE Immunology and Infection
A Primary Neuron Culture System for the Study of Herpes Simplex Virus Latency and Reactivation
1Department of Microbiology, New York University School of Medicine, 2Molecular Neurobiology Program, Skirball Institute for Biomolecular Medicine, New York University School of Medicine, 3Department of Otolaryngology, New York University School of Medicine, 4Department of Cell Biology, New York University School of Medicine, 5Department of Physiology and Neuroscience, New York University School of Medicine, 6Department of Psychiatry, New York University School of Medicine, 7Center for Neural Science, New York University School of Medicine
The protocol describes an efficient and reproducible model system to study herpes simplex virus type 1 (HSV-1) latency and reactivation. The assay employs homogenous sympathetic neuron cultures and allows for the molecular dissection of virus-neuron interactions using a variety of tools including RNA interference and expression of recombinant proteins.
JoVE General
In vivo Bioluminescent Imaging of Mammary Tumors Using IVIS Spectrum
Biology Research and Development , Caliper Life Sciences
Mammary tumor cells expressing luciferase are implanted subcutaneously in mice and visualized using optical imaging to monitor tumor growth and development non-invasively in a longitudinal study.
JoVE General
Single-cell Suction Recordings from Mouse Cone Photoreceptors
We will show how to record flash responses from single mouse cones using a suction electrode.
JoVE Editorial
June 2011: This Month in JoVE
Here are some highlights from the June 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE General
Direct Observation of Enzymes Replicating DNA Using a Single-molecule DNA Stretching Assay
We describe a method for observing real time replication of individual DNA molecules mediated by proteins of the bacteriophage replication system.
JoVE General
Noninvasive In Vivo Small Animal MRI and MRS: Basic Experimental Procedures
1Department of Radiology, University of Washington, 2Department of Bioengineering, University of Washington
This work describes basic procedures of noninvasive small animal MRI and MRS in vivo.
JoVE General
Detection of Nitric Oxide and Superoxide Radical Anion by Electron Paramagnetic Resonance Spectroscopy from Cells using Spin Traps
1The Davis Heart and Lung Research Institute, The Ohio State University, 2Department of Pharmacology, College of Medicine, The Ohio State University
Electron paramagnetic resonance (EPR) spectroscopy was employed to detect nitric oxide from bovine aortic endothelial cells and superoxide radical anion from human neutrophils using iron (II)-N-methyl-D-glucamine dithiocarbamate, Fe(MGD)2 and 5,5-dimethyl-1-pyroroline-N-oxide, DMPO, respectively.
JoVE General
Measuring Exocytosis in Neurons Using FM Labeling
Department of Molecular and Cell Biology, Harvard
The ability to measure the kinetics of vesicle release can help provide insight into some of the basics of neurotransmission. Here we used real-time imaging of vesicles labeled with the red fluorescent dye FM 4-64 to measure the rate of presynaptic vesicle release in hippocampal neuronal cultures.
JoVE General
Generating iPS Cells from MEFS through Forced Expression of Sox-2, Oct-4, c-Myc, and Klf4
Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology
This video shows the procedure for generating induced pluripotent stem cells using inducible lentivirus that express Oct4, Sox2, c-Myc and Klf4.
JoVE General
Primary Dissociated Midbrain Dopamine Cell Cultures from Rodent Neonates
Department of Pharmacology and Experimental Therapeutics, Tufts University
Primary dissociated midbrain dopamine cell cultures allow for the study of presynaptic characteristics of dopamine neurons. They can be used to monitor real-time dopamine release kinetics and protein/mRNA levels of regulators of dopamine exocytosis. Here, we show you how to generate these cultures from rodent neonates.
JoVE General
Historical View and Physiology Demonstration at the NMJ of the Crayfish Opener Muscle
Department of Biology, University of Kentucky
The opener muscle of the crayfish leg is presented for its historical importance and experimental versatility in muscle phenotype, synaptic physiology and plasticity.
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